package T1;

public class Circle {

        double r;
        double PI = 3.14;

        public  Circle(){
         r=10;
        }
        public  Circle(double r){
            this.r = r;
        }
        public void Area(){
            System.out.println("面积为"+r*r*PI);
        }

        public void Girth(){
            System.out.println("周长为"+2*r*PI);
        }
}

